After buying it last week, I set it in a rechargeable hand drill and drilled hard stainless steel (SUS 304), but I made it possible to break two holes so as not to break. From long ago, this hand drill was sharpening the teeth several times on the way. This drill was able to open a hole of 1.5 mm even when cutting fluid was not applied. Currently it is possible to open SUS 304 material with a drilling machine without problems with a hole of 1.2 mm. Even if you look at the condition of the use of teeth, it seems to be possible to use until breakage if you do not cut cutting fluid! Later, I will also challenge the hole of SUS 316 ~